Potassium Carbonate → 5-(2-methoxyethoxy)-1H-indole

HRID 41062

Reaction equation

HRID 41062 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[CH:5]2.[CH3:11][O:12][CH2:13][CH2:14]I.CC(C)=O.C([O-])([O-])=O.[K+].[K+].COCCI>C1(C)C=CC=CC=1.CC(C)=O>[CH3:11][O:12][CH2:13][CH2:14][O:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[CH:5]2

Participants

6

Reactant 4

HCID 11430Potassium Carbonate2×HCID 160545-HydroxyindoleHCID 791361-Iodo-2-methoxyethaneHCID 86634331Acetone 2-methoxyethyl iodide

Product 1

HCID 103525375-(2-methoxyethoxy)-1H-indoleYield 86.2%

Reagents, catalysts & solvents 1

HCID 20247278Toluene acetoneSolvent

Procedure

To a solution of 5-hydroxy-indole (15.2 g, 114 mmol) in 250 ml of dry acetone 2-methoxyethyl iodide (15 ml, 141 mmol, 1.25 equiv) and anhydrous K2CO3 (46.7 g, 338 mmol, 3 equiv) are added and the mixture is refluxed. Additional amounts of 0.5 equiv of 2-methoxyethyl iodide and K2CO3 are added each day. After 6 days TLC (toluene-acetone, 9:1) indicates the absence of starting material. The solid is removed by filtration, and the solvent is evaporated. The residue is taken up in dichloromethane (800 ml) and the solution is washed with 2 M aqueous HCl, 10% aqueous NaHCO3, and water. The organic layer is dried and concentrated. Column chromatography (toluene-acetone, 9:1) provides 5-(2-methoxyethoxy)-1H-indole (18.8 g, 86%). M.p. 58-60° C. (from ethyl acetate-light petroleum).

Workup

  1. temperaturethe mixture is refluxed
  2. customThe solid is removed by filtration
  3. customthe solvent is evaporated
  4. washthe solution is washed with 2 M aqueous HCl, 10% aqueous NaHCO3, and water
  5. customThe organic layer is dried
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-a397b75c02ed433587cf9bf2dbd0b0f4
Source dataset
uspto-grants-2013_09
Patent number
US08530493B2

Linked notes

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